Tax & Paycheck Guides
In-depth explanations of the rules behind our calculators, written from IRS and state sources and reviewed against our methodology. All 19 guides are organized into five topic areas.
Paychecks & Withholding
How your paycheck is built: the W-4, pay stubs, overtime, tips and bonus withholding.
How to Read Your Pay Stub: Every Line Explained
A plain-English walkthrough of a US pay stub: gross pay, federal and state withholding, Social Security, Medicare, pre-tax deductions, YTD totals and how to spot errors.
9 min read · Updated October 2026
Paychecks & WithholdingHow to Fill Out Form W-4: A Step-by-Step Guide
What each step of the IRS Form W-4 means, how it changes your paycheck, and how to avoid a big tax bill or an oversized refund. Includes examples for two-earner households and side income.
10 min read · Updated October 2026
Paychecks & WithholdingWhy Is My Bonus Taxed So Much? Supplemental Wage Withholding Explained
How US employers withhold tax on bonuses, the 22% and 37% federal supplemental rates, aggregate vs. percentage methods, state rates, and why the final tax is usually lower than it looks.
8 min read · Updated October 2026
Paychecks & WithholdingHow Overtime Pay Is Taxed: Federal Rules & the 2026 Deduction
How overtime is calculated under the FLSA, why overtime checks seem over-taxed, the new federal deduction for qualified overtime (2025–2028) and state rules like California daily overtime.
9 min read · Updated October 2026
Paychecks & WithholdingTip Income: Reporting Rules and Taxes for Service Workers
How tips are taxed in 2026: reporting to your employer, Form 4070 and 4137, cash vs. card tips, tip pooling, the new deduction for qualified tips and how withholding works.
9 min read · Updated October 2026
Deductions & Credits
Tax breaks that lower your bill: child tax credit, EITC, health accounts and the standard vs. itemized choice.
Child Tax Credit & EITC Explained (2026)
How the Child Tax Credit and Earned Income Tax Credit work in 2026: amounts, refundable portions, income phase-outs, qualifying child rules and common mistakes that delay refunds.
9 min read · Updated October 2026
Deductions & CreditsHSA vs. FSA: Which Health Account Saves You More?
Compare Health Savings Accounts and Flexible Spending Accounts for 2026: contribution limits, eligibility, the triple tax advantage, use-it-or-lose-it rules and how to choose.
9 min read · Updated October 2026
Deductions & CreditsStandard Deduction vs. Itemizing: How to Choose
What the standard deduction is, which expenses can be itemized (mortgage interest, SALT, charity, medical), and a simple test to decide which option lowers your federal tax.
8 min read · Updated October 2026
Investments & Retirement
Taxes on investment gains and retirement accounts: capital gains, 401(k)s and IRA choices.
Short-Term vs. Long-Term Capital Gains Tax (2026 Rates)
How capital gains are taxed in 2026: the 12-month holding rule, 0%/15%/20% long-term brackets, short-term gains at ordinary rates, the 3.8% NIIT and how losses offset gains.
9 min read · Updated October 2026
Investments & RetirementRoth IRA vs. Traditional IRA: Rules & Limits (2026)
Roth vs. traditional IRA for 2026: $7,500 contribution limit, catch-up, Roth income phase-outs, deductibility rules, withdrawal rules and how to decide which fits your tax bracket.
10 min read · Updated October 2026
Investments & RetirementHow 401(k) Contributions Affect Your Paycheck and Taxes
Traditional vs. Roth 401(k), how pre-tax contributions lower income tax but not FICA, the real cost per paycheck, employer matches and how to pick a contribution rate.
9 min read · Updated October 2026
Self-Employment & 1099
For freelancers and gig workers: self-employment tax, quarterly estimates, home office and mileage deductions.
Self-Employment Tax Explained: How 1099 Workers Are Taxed
How self-employment tax works for freelancers, contractors and gig workers: the 15.3% rate, the 92.35% rule, the deduction for half, the QBI deduction and real examples.
10 min read · Updated October 2026
Self-Employment & 1099Quarterly Estimated Taxes: Deadlines, Safe Harbors and How Much to Pay
Who must pay estimated taxes, the four IRS due dates, the 90% / 100% / 110% safe-harbor rules, how to pay, and how to avoid the underpayment penalty.
9 min read · Updated October 2026
Self-Employment & 1099Home Office Deduction: Simplified vs. Regular Method
Who qualifies for the home office deduction, the exclusive and regular use test, the $5-per-square-foot simplified method vs. actual expenses, depreciation recapture and examples.
9 min read · Updated October 2026
Self-Employment & 1099Standard Mileage Rate vs. Actual Car Expenses
How to deduct business driving in 2026: the IRS standard mileage rate, the actual expense method, depreciation, the first-year rule, logbook requirements and examples for gig drivers.
9 min read · Updated October 2026
IRS Rules & Life Events
How the tax code treats big moments: brackets, states without income tax, amended returns, gifts and inheritances.
How Tax Brackets Really Work: Marginal vs. Effective Tax Rate
Why a raise never lowers your take-home pay, how US marginal brackets apply only to the dollars inside each band, and how to calculate your real effective tax rate.
8 min read · Updated October 2026
IRS Rules & Life EventsStates With No Income Tax: What You Really Save
The nine US states that don't tax wages, how they raise revenue instead (sales, property, excise taxes), and how to compare the true cost of living in a no-tax state.
8 min read · Updated October 2026
IRS Rules & Life EventsHow to File an Amended Tax Return (Form 1040-X)
When and how to amend a federal tax return with Form 1040-X: deadlines, e-filing, what to include, how long refunds take, state amendments and mistakes that don't need an amendment.
8 min read · Updated October 2026
IRS Rules & Life EventsGift Tax Rules & the Lifetime Estate Exemption (2026)
How the federal gift tax works in 2026: the $19,000 annual exclusion, the $15 million lifetime exemption, Form 709, gifts to spouses, tuition and medical exclusions and state estate taxes.
9 min read · Updated October 2026